Ali is unhappily married to Colin, and as the book progresses, we can see why. He's emotionally abusive, although none of the characters nor the author seem to realise this. Ali enjoys her job and seeks comfort and distraction through her work, her colleagues and her friend. She's obsessed with her competence as a mother and spends (too) much of the narrative going on about it, which is made even more irritating because keeps referring to herself as a mummy. Eventually things come to a head, the marriage comes to a crisis, and a resolution is reached.
The dialogue is very odd in places, the character of Colin is so unpleasant it's hard to see why anyone would want to stay with him, and the ending all feels a bit meh.